• Microbiology and Biotechnology Letters
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• v.21 no.5
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• pp.414-420
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• 1993

Escherichia coli mrdAts and mrdBts mutants forming spherical cells at 42C, were employed to investigate the possible role of both inner and outer membrance structures in the determination of cell shape of gram-negative cells. Spherical cells, but not rod-shaped wild types, were specifically killed by anionic detergents, such as sarkosyl, sodium dodecylsulfate and sodium deoxycholate. From the spherical intact cells grown overnight at 42C, much more proteins were released by sakosyl.

• Journal of the Korean Ceramic Society
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• v.27 no.6
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• pp.729-734
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• 1990

The microstructural dependence of thermal conductivity of a high-alumina (ca. 70%) heat-insulating frebricks(ca. 75%porosity) was investigated under special consideration of the tailored-pore shape effects. Pores different shape could be incorporated into the insulators through pore formers : Styrofoam produces spherical pores while saw dust results in parallel plate pores. Concerning the pore-shape effectiveness of thermal insulation, the specimen with irregular plate pores showed much lower values of heat conductivity than those with spherical pores, the values being 0.31 to 0.38 at $600^{\circ}C$ and 0.35 to 0.47 at 100$0^{\circ}C$, respectively. On the contrary, however, other material properties such as strength and softening temeprature under load were turned out to be better in the case of the spherical pores.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.11
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• pp.964-971
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• 2002

A numerical investigation of the constrained melting of phase change materials within spherical-like capsule is presented. A single-domain enthalpy formulation is used for simulation of the phase change phenomenon. The solution methodology is verified with the melting process inside an isothermal spherical capsule. Especially, the effect of capsule shape on the heat storage is emphasized. Two shape parameters are considered from the real capsule shape showing good characteristics of heat storage and the effect of these parameters is examined. Early during the melting process, the conduction mode of heat transfer is dominant. Thus the capsule shape with large surface area is desirable. However, the capsule shape with large surface area plays negative role on the strength of buoyancy-driven convection that becomes more important as melting continues.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1060-1062
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• 2002

Spherical and dense BAM phosphor particles were prepared by spray pyrolysis. The key idea of dense BAM particles is to lead gelation in droplets, which was successfully achieved by using the aluminum polycation as the precursor solution for the spray pyrolysis. The BAM phosphor particles prepared by spraying the aluminum polycation solution have completely spherical shape and dense structure. When directly applied to make phosphor film on the glass by the screen-printing method, the prepared spherical BAM phosphor particles showed better packing density and surface morphology than that of commercial one, which has irregular shape and large particle size. It was also found that the thermal degradation in the photoluminescence intensity for dense and spherical BAM particles was less than that of commercial one.

• Journal of Environmental Science International
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• v.26 no.12
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• pp.1333-1339
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• 2017

Coal-fired power plants emit various Particulate Matter(PM) at coal storage pile and ash landfill as well as the stack, and affect the surrounding environment. Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray analyzer(FE-SEM/EDX) were used to develop identification factor and the physico-chemical analysis of PM emitted from a power plant. In this study, three samples of pulverized coal, bottom ash, and fly ash were analyzed. The pulverized coal was spherical particles in shape and the chemical composition of C-O-Si-Al and C/Si and C/Al ratios were 200~300 on average. The bottom ash was spherical or non-spherical particles in shape, chemical composition was O-C-Si-Al-Fe-Ca and C/Si and C/Al ratios were $4.3{\pm}4.6$ and $8.8{\pm}10.0$. The fly ash was spherical particles in shape, chemical composition was O-Si-Ai-C-Fe-Ca and C/Si and C/Al ratios were $0.5{\pm}0.2$ and $0.8{\pm}0.5$.

• Current Optics and Photonics
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• v.3 no.1
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• pp.72-77
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• 2019

This study was performed to analyze the optical aberrations of the cornea induced by myopic refractive surgery. Corneal total higher-order aberrations, spherical aberration and coma for 4-mm and 6-mm pupils were measured using a wave-front analyzer. The amount of aberrations of the oblate corneal optics by the achieved correction was found to be larger than for the prolate corneal shape with complete eye, in an emmetropia control group. The change in corneal shape acts as an optical factor that degrades the quality of the retinal image; it seems to be one of the important factors related to quality of vision.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.3
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• pp.127-131
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• 2001

The effect of grain shape on the grain growth behavior of oxide system was investigated as afunction of liquid content during liquid phase sintering. As a model system, the solid grains of $Al_{2}O_{3}$ and MgO were selected during liquid phase sintering, i.e. faceted shape of $Al_{2}O_{3}$ in $CaAl_{2}Si_{2}O_{8}$ liquid phase and spherical shape of MgO in $CaMgSiO_{4}$ liquid phase. The average grain size of MgO with spherical shape was decreased with increasing the liquid phase content, whereas that of $Al_{2}O_{3}$ with faceted shape was independent of liquid phase content. In the case of $Al_{2}O_{3}$ grains with faceted shape, which interfaces are expected to be atomically flat, are likely to grow by the interfacial reaction controled process. Whereas, in the case of MgO grains with spherical shape, which interface are expected to be atomically rough, are likely to grow by the diffusion controlled process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.1028-1032
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• 1995

This paper describes the manufacture of spherical and aspherical surface on glass, superalloy and ceramic components. The rotationally symmetricallenses, and the ceramic or superalloy molds with spherical shapes are mainly generated by cutting processes on CNC lathe machine or 4,5 axis CNC machining centers. Recently, spherical shape parts require more precise and efficent machining technologies for wide material range such as optical lens of the lithography device in semiconductor manufacturing processes or the high precision mold machining of anti-chemical, anti-wear materials. In this paper, we introduce a newly developed infeed grinding machine with metal with metal bonded cup type wheel and its effects on spherical surface grinding.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.6
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• pp.530-536
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• 2016

The number of fabrication shop for spherical type LNG tank is proportional to that of the tank radius to be constructed. Due to limitation of facility investment including building sites, it is practically difficult to fabricate various size tanks with perfectly spherical shape in the yards. The efficient method to be capable of increasing cargo tank volume is to extend vertically the conventional spherical type LNG tank by inserting a cylindrical shell structure. The main purpose of this study is to derive related equations on forces generated on spherical type LNG tank with central cylindrical part under various static loadings in order to establish the simplified analysis method for the initial estimate. In this study, equations on circumferential and meridional force have been derived and verified by relations with the reaction forces per unit length of equator.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.05a
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• pp.169-175
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• 2004

Researches on spherical shell which is most usually applied have been completed by many investigators already and generalized numerical formula was derived. But the existent researches are limited to those on spherical shell with isotropic or orthotropic roof stiffness, periodic distribution of roof stiffness that can be caused by spherical and latticed roof system is not considered. Therefore, this paper is to develop a structural analysis program to analyze spherical shells that have periodicity of roof stiffness distribution caused by latticed roof of large space structure, grasp buckling characteristics and behavior of structure.